Fluid-controlled selection system

ABSTRACT

A fluid-controlled selection system having a number of logical fluid elements, each of which has a pressure output communicating with a pressure input. In the communication between a pressure input and a pressure output at least two series-arranged fluid interrupters are incorporated. The said fluid interrupters in each logical fluid element are controlled by means of control signals originating from a combination of two control pressure lines from a total number of control pressure lines for the entire selection system, this combination being different for each fluid element.

United States Patent Kraakman FLUID-CONTROLLED SELECTION SYSTEM [72] Inventor: Hillebrand Johannes Kraakman, Emmasingel,

hoven, Netherlands Assignee: U.S. Philips Corporation,

York, NY.

[22] Filed: April 22, 1971 [21] Appl. No.: 136,462

Josephus End- New

[30] Foreign Application Priority Data April 25, 1970 Netherlands ..7006059 [52] U.S. Cl. ..200/83 R, 137/608, 179/18 GF, 200/DIG. 43, 200/81.4, 200/83 N [51] Int. Cl. ..H 01h 35/24, HOlh 35/34 [58] Fieldof Search ..200/81 R, 81.4, 83 R, 83 N, 200/175, 178, 81.5, 81.6; 179/18 G, 18 F;

340/166; 235/200 R, 200 P, 200 F, 201 R,

[56] References Cited Y UNITED STATES PATENTS 7 3,304,386 2/1967 Shelesinger, lr... ....200/178 X Nov. 14, 1972 3,493,173 2/ 1970 Monge et a1. ..235/200 PF 3,599,525 8/1971 Klann 137/608 X 2,811,599 10/1957 Statham ..200/83 N 3,571,542 3/1971 Madden et a]. ..200/83 N 3,531,079 9/1970 Greene ..25l/61.1 3,540,477 1 1/1970 Hogel 1 37/608 Primary Examiner-Robert K. Schaefer Assistant Examiner-Robert A. Vanderhye Attorney-Frank R. Trifari [57] ABSTRACT A fluid-controlled selection system having a number of logical fluid elements, each of which has a pressure output communicating with a pressure input. In the communication between a pressure input and a pressure output at least two series-arranged fluid interrupters are incorporated. The said fluid interrupters in each logical fluid element are controlled by means of control signals originating from a combination of two control pressure lines from a total number of control pressure lines for the entire selection system, this combination being different for each fluid element.

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AGEN T in many cases undesirable to use eq 1 FLUID-CONTROLLED SELECTION SYSTEM The invention relates to a fluid-controlled selection system for the selective transmission of a fluid pressure to fluid-controlled devices to be connected to outputs of the selection system.

ln contemporary data processing technics, not only a need exists for extremely fast, electronic equipment, but also an ever growing need for comparatively slower operating devices which are rugged, firesafe and comparatively inexpensive. For the control of, for example, chipping machines, it is often only necessary to supervise given process parameters and to intervene only if these assume inadmissible values, so that for this purpose it is uneconomical to use expensive electronic equipment which in general, is not capable of withstanding rough operation. In, for example, the chemical and petro-chemical industries, moreover, it is pmeht imposing even the slightest risk of spark-formation.

Fluid-controlled devices are known to be used in order to avoid the abovementioned problems. Such devices offer the advantage that they are rugged, firesafe and comparatively inexpensive. The lower speed of such devices is no objection in many cases.

The object of the invention is to provide an in itself simple fluid-controlled system which is in principle suitable for controlling given processes and which offers many extension possibilities for processing many types of information. 7 7

The invention is therefore characterized in that the selection system comprises a number (n) of logical.

fluid elements, each of which has a pressure output communicating with a pressure input, said communication incorporating at least two (m) fluid interrupters which are arranged in series and which are to be individually operated by a control signal supplied thereto, said system communicating with a number (x) of control pressure lines for the selective control of the logical fluid elements, fluid interrupters of the various logical fluid elements to be operated by a control signal communicating with these control pressure lines so that each of the various fluid interrupters of one and the same logical fluid element communicates with a different control pressure line and the fluid interrupters of the various logical fluid elements each time communicate with a different combination of control pressure lines from the total number (x) of control pressure lines.

In order that the invention may be readily carried into effect, some embodiments thereof will now be described in detail, by way of example, with reference to the accompanying diagrammatic drawings, in which:

FIG. 1 diagrammatically shows a first embodiment of a selection system according to the invention, having ten fluid elements which are selectively controlled by means of five control pressure lines.

FIG. 2 shows a diaphragm straight way valve which may be applied in the selection systems according to the invention.

FIG. 3 diagrammatically shows a second embodiment of a selection system according to the invention, having eight fluid elements which are selectively controlled by means of three pairs of control pressure lines.

FIG. 4 shows an automatically operating diaphragm valve which may be applied in the selection systems according to the invention.

FIG. 5 diagrammatically shows the pattern of the communications of the fluid interrupters in the various fluid elements with the control pressure lines for the selection system shown in FIG. 3.

FIG. 6 diagrammatically shows a third embodiment of a selection system according to the invention, having eight fluid elementswhich are selectively controlled by three pairs of control pressure lines, each pair having inverse pressure levels.

FIG. 7 diagrammatically shows the pattern of the communications of the fluid interrupters in the various fluid elements with the control pressure lines for the selection system shown in FIG. 6. v

FIG. 8 diagrammatically shows a fourth embodiment of a selection system according to the invention, having eight fluid elements which are selectively controlled by three pairs of control pressure lines.

FIG. 9 diagrammatically shows a plunger valve which may be applied in the selection system according to the invention. I

FIG. 10 diagrammatically shows a fifth embodiment of a selection system according to the invention.

FIG. 11 diagrammatically shows a sixth embodiment of a selection system according to the invention, a selection system of the type shown in FIG. 10 being coupled to a selection system of the type shown in FIG. 6

The connecting FIGS. 12 and 13 show a section of a combination of two selection systems according to the invention which is suitable as a coordinate switch for automatic telephony. A

FIG. 14 shows a section of a fluid-controlled threeway contact which may be used for automatic telephony in the combination of selection systems shown in the FIGS. 12 and 13.

FIG. 15 shows a block diagram of the combination of selection systems shown in the FIGS. 12 and 13.

The selection systems illustrated by the FIGS. 1, 3, 5, 6, 7, 8, 10, 11, 12, 13 and 15 are all operated with fluid (in general air) of a binary (inverse) pressure level, i.e. pressures of a comparatively high and a comparatively low level (henceforth called pressure levels 1 and 80,). 7 v I. I

The selection system 3 shown in FIG. 1 comprises ten identical logical fluid elements 5 to be selectively controlled, only four of which are shown. Each of these ten fluid elements 5 is provided with two series-arranged fluid interrupters, each of which is to be operated by a control signal to be supplied thereto, each of the interrupters being incorporated in the communication between a pressure input and a pressure output. For example, the fluid element 5 shown is provided with the series-arranged fluid interrupters 11 and 13, communicating with control pressure lines a and b via signal supplies 7 and 9, said interrupters being incorporated in the communication between pressure input 15 and pressure output 17. The pressure level at a pressure input is transmitted to the associated pressure output, i.e. the relevant fluid element is selected, only if the control pressure lines communicating with the relevant fluid element have the same pressure level. The pressure input of each fluid element communicates with a command pressure line S which is common to all fluid elements and which may have the pressure level,

. further fluid-controlled devices.

The selection of one particular fluid element out of the ten fluid elements 5 of the selection system 3 is effected by means of five control pressure lines a, b, c, d and e. For this purpose the two fluid interrupters of each fluid element 5 communicate each time withadifferent combination of two of the control pressure lines a, b, c, d and e. As already described, the fluid interrupters l1 and 13 communicate via the signal supplies 7 and 9 with the control pressure lines a and b, respectively. The remaining nine fluid elements 5 successively communicate with the following combinations of control pressure lines:

ssws someone It may thus be seen from the foregoing that by means of five control pressure lines, each of which may each have the pressure level l or 0, at the most ten different fluid elements may be selectively controlled, for selection of one particular fluid element where the two associated control pressure lines both have to have either the pressure level 1 or 0,. All control pressure lines not communicating with that fluid element also have either the pressure level 0 or I. That is, in any system of five variables there are only 10 possible exclusive combinations of two selected variables. When the shown fluid element 5 is selected, this means that the control pressure lines a and b have the pressure level 0, and the control pressure lines 0, d, e have the pressure level I, or that the control pressure lines a and b have the pressure level l, and the control pressure lines 0, d and e have the pressure level 0. In accordance with the type of fluid interrupter (which will be discussed in detail with reference to FIG. 9), it is brought into the closed position by a control signal of the level l or of the level 0. In the selection system 3, for example, the fluid interrupter 19 shown in FIG. 2 is used, which is closed when a control signal of the level l is supplied.

The fluid interrupter 19 (called straight way valve 19 henceforth) comprises two circular compartments 21 and 23, which are separated from each other by a flexible diaphragm 35 of, for example, Ni foil. The compartment 21 communicates with a signal supply 27, whilst the compartment 23, separated from the compartment 21, communicates with a fluid duct 29 and a fluid duct 31 communicating therewith, respectively. In the case of a pressure level 1 at both sides of the diaphragm 25, the straight way valve 19 is in the closed condition.

By means of a selection system as shown in FIG. 1 it is possible to select two or more fluid elements successively and to keep these fluid elements in the selected condition simultaneously. In that case the pressure level combination by means of which the last selected fluid element has been selected,is to be maintained. As a result, always one of the straight way valves of a previously selected fluid element is closed so that, in the absence of leakage losses, the pressure level at the relevant pressure output is maintained. Returning one particular fluid element to the non-selected condition is to be effected by reselecting that fluid element and inverting the pressure level of the command pressure line- By using pressure level combinations other than stated above, various fluid elements may also be selected simultaneously by means of the selection system 3 and be kept in the selected condition by maintaining the said pressure level combination. Returning simultaneously selected fluid elements is efiected by inverting the command pressure line at that pressure level combination.

The selection system 33 shown in FIG. 3, which is a second embodiment of a selection system according to the invention, comprise eight (n) identical fluid elements 35, each of which is provided with three (m) series-arranged straight way valves, for example, as shown in FIG. 2. Consequently, for the selection system 33, n 2". The selective control of the eight fluid elements is effected by means of six control pressure lines a, b, c, d, e and f. For the sake of clarity only one of the fluid elements 35 and its connections to the control pressure lines is shown. A fluid element 35 comprises three series-arranged straight way valves 37, 39 and 41, via which a pressure input 43 communicates with a pressure output 45. The pressure input 43 communicates with a command pressure line S which is common to all eight fluid elements 35. The valves 37, 39 and 41 are connected to one of the control pressure lines a, b, c, d, e and f by means of signal supplies p, q and r, respectively. With each of the straight way valves a further fluid interrupter is associated which is connected on one side to the pressure output 45 and on the other side, via a signal supply, to one of the control pressure lines a, b, c, d, e and f. With the straight way valves 37, 39 and 41, thefluid interrupters 47, 49 and 51 are associated respectively, which are provided with the signal supplies 5, t and u respectively, each of which is connected to one of the control pressure lines a, b, c, d, e and f. The fluid interrupters 47, 49 and 51 are, for example, of the type shown in FIG. 4. The fluid interrupter 53 shown in FIG. 4 comprises two circular compartments 55 and 57 which are separated from each other by a flexible diaphragm 59 of, for example, nickel foil which is provided with an aperture 61. The compartment 55 is provided with a fluid duct 63 and the compartment 57 with a fluid duct 65. The distance between the diaphragm 59 and the face 67, serving as a stop, may be chosen to be such that the communication between fluid duct 63 and fluid duct 65 is cut off only at a very specific positive pressure differential between the compartment 55 and the compartment 57. This will be discussed in detail hereinafter.

Hereinafter, the fluid interrupters shown in FIG. 4 will often be called automatically operating fluid interrupters in order to distinguish them from the fluid interrupters shown in FIG. 2. The automatically operating fluid interrupters 47, 49 and 51 (FIG. 3) will hereinafter be called air-relief valves 47, 49 and 51 in view of their function in the selection system 33. The control pressure lines a, b, c, d, e and f pairwise always have mutually inverse pressure levels, i.e. if the control pressure in control pressure line a is of the level l (comparatively high level), the control pressure in the control pressure line b is of the level 0 (comparatively low level), or vice versa. The same holds good for the pairs of control pressure lines c, d and e, f.

The signal supplies p, q and r of the three straight way valves are each time connected to a different combination of three control pressure lines for the various fluid elements 35. The signal supplies s, t and u of the associated air-relief valves in such a fluid element are then connected to the other three control pressure lines. The signal supplies p, q and r of the fluid element 35 shown are connected to the control pressure lines a, c and e respectively, whilst the signal supplies s, t and u are connected to the control pressure lines b, d and f.

FIG. 5 diagrammatically shows the connections of the signal supplies of each of the eight fluid elements 35 in the selection system 33 as shown in FIG. 3. The signal supplies p and s of each fluid element 35 are always connected to one of the control pressure lines a and b, the signal supplies q and t are always connected to one of the control pressure lines and d, and the signal supplies r and u are always connected to one of the control pressure lines e and f. The said method of connecting the signal supplies, as shown in FIG. 5, offers a very simply designed system of connections incorporating short signal supplies p, q, r, s, t and u and straight control pressure lines a, b, c, d, e and f extending through the entire selection system,- cross-overs of signal supplies and control pressure lines in a fluid element being avoided (compare with the selection system 3 shown in FIG. 1

The operation of the selection system 33 is described with reference to one particular pressure level combination in the control pressure lines a, b, c, d, e and f, i.e. the combination where the fluid element 35 illustrated in FIGS. 3 and 5 is selected. The following reference numerals now only refer to the shown and selected fluid element 35. It is assumed that the command pressure line S, which is common to all eight fluid elements 35, continuously has the pressure level 1, so that also all eight pressure inputs 43 continuously have the pressure level 1, and the control pressure lines a, b, c, d, e and f have the pressure level 0, b, 0, l, 0 and 1, respectively. As each of the control pressure lines a, c and e has the pressure level 0, the respective straight way valves 37, 39 and 41 are opened so that the pressure output 45 has the pressure level l As control pressure lines b, d and f have the pressure level l so that at both sides of the airrelief valves 47, 49 and 51 the pressure level I prevails, the pressure level l on the control pressure output 45 cannot drop. It will be obvious that in none of the remaining seven fluid elements 35 the pressure level l appears at the relevant pressure output because in those fluid elements at least one straight way valve is closed at the assumed pressure level combination in the control pressure lines (see FIG. 5), whilst also at least one associated air-relief valve, communicating with a control pressure line having the pressure level 1,? is closed.

By selecting a fluid element other than the fluid element 35 shown and selected, at least one of the straight way valves 37, 39 and 41 closes, in which case the pressure level l prevails at the side of the air-relief valve, associated with that straight way valve, which faces the pressure output 45, whilst at the other side of that straight way valve, which communicates with a control pressure line which now has the pressure level 0," pressure level 0 prevails. As a result, the pressure output 45 of the fluid element 35 is relieved via the said air-relief valveas far as the first closed straight way valve (viewed from the pressure output 45).

As the control pressure lines a and b, c and d and e and f always have an inverse pressure level, the pairs of inverse control pressure lines a and b, c and d and e and f may be controlled by one control element per pair of inverse control pressure lines. In comparison with the selection system 3 shown in FIG. 1, where no pair-wise pressure inverse control pressure lines are used, in the selection system 33 shown in FIGS. 3 and 5 six control pressure lines may be controlled by means of only three control elements, whilst in the selection system 3 five control pressure lines are controlled by five control elements (one control element for each control pressure line). On the other hand, in the selection system 3 ten different fluid elements may be selected by means of five control pressure lines, whilst in the selection system 33 only eight fluid elements maybe selected by means of six control pressure lines. Particularly in the case of a comparatively large number of fluid elements to be selected the selection system 33 shown in FIG. 3 and in FIG. 5, however, offers the special advantage that the control pressure lines and the signal supplies can be so arranged that no cross-overs between control pressure lines and signal supplies are necessary (see FIG. 5). Specially viewed, of each pair of pressure-inverse control pressure lines one control pressure line is therefore arranged to the one side of the straight way or air-relief valves, respectively, corresponding in place in the consecutive fluid elements, whilst the other control pressure line is arranged to the other side of said valves. In the selection system 3 shown in the FIG. 1, this is not possible withoutcross-overs of control pressure lines and signal supplies.

The third embodiment of a selection system 69 according to the invention shown in FIG. 6 comprises eight identical fluid elements 71 which are to be selected individually and which are provided with three series-arranged straight way valves (for example, as shown in the FIG. 2), via which valves a command pressure line S which is common to all fluid elements communicates with the pressure output of the consecutive fluid elements, an automatically operating fluid interrupter (for example, as shown in FIG. 4) being associated with each straightway valve. For the sake of clarity only one the fluid elements 71 is shown. Each fluid element 71 is provided with three series-arranged straight way valves 73, 75 and 77, with which the automatically operating fluid interrupters 79, 81 and 83 respectively, are associated.

The straightway valves 73, 75 and 77 communicate with one of the six control pressure lines a, b, c, d, e and f via the signal supplies p, q and r. Via the straight way valves 73, 75 and 77, a pressure input communicating with the command pressure lines S communicates with a pressure output 87. The automatically operating fluid interrupters 79, 81 and 83 of each fluid element communicate on the one side with the pressure output of that fluid element and on the other side, via the said signal supplies p, q and r, with one of six control pressure lines a, b, c, d, e and f which pairwise have inverse pressure levels. The signal supplies p, q and r of a fluid element 71 are therefore common to the straight way valves 73, 75 and 77 and the automatically operating fluid interrupters 79, 81 and 83 associated therewith, so that a control pressure line communicating with a straight way valve also communicates with the automatically operating fluid interrupter associated with that straightway valve. The signal supplies p, q and r of the various fluid elements 71 each time communicate with another combination of three control pressure lines.

FIG. 7 diagrammatically shows the connections of the signal supplies of each of the eight fluid elements 71 in the selection system 69 (as shown in FIG. 6).

The operation of the selection system 69 will now be described with reference to a pressure level combination in the control pressure lines, a, b, c, d, e and f where the shown fluid element 71 is selected, i.e. O, l, 0, 1, 0, 1. As the straight way valves 73, 75 and 77 are opened at this pressure level combination, a pressure of the level present in the command pressure line S appears at the pressure output 87. As the pressure level 0 prevails both on the side of the automatically operating fluid interrupters 79, 81 and 83 facing the signal supplies p, q and r and the side facing the pressure output 87, the pressure level 0 at the pressure output 87 is maintained. If one of the other seven fluid elements 71 in the selection system 69 is selected whilt the shown fluid element 71 has been selected, so that in at least one pair of control pressure lines the pressure level is inverted, at least one of the straight way valves closes and the automatically operating fluid interrupter associated with that straightway valve opens so that via this open fluid interrupter pressure of the level 1 appears at pressure output 87.

The fourth embodiment of a selection system 87 according to the invention shown in FIG. 8 comprises eight identical fluid elements 89 which are to be in dividually selected and which are each provided with three series-arranged straight way valves (for example, as shown in FIG. 2) communicating with one of six control pressure lines a, b, c, d, e and f via signal supplies p, q and r, a command pressure line S which is common to all fluid elements communicating with pressure outputs of the consecutive fluid elements via said straight way valves. With each straight way valve an additional similar straight way valve is associated which commu-' nicates via one of the signal supplies s, t and u with one of the control pressure lines a, b, c, d, e and f. The signal supplies p, q, r, s, t and u communicate with the control pressure lines a, b, c, d, e and fin the same manner as shown in FIG. 5 for the selection system 33, whilst also in this case the control pressure lines of the pairs of control pressure lines a and b, c and d, e and f always have inverse pressure levels. For the sake of clarity only one of the eight fluid elements 89 is shown. Each fluid element 89 is provided with three series-arranged straight way valves 91, 93 and 95, with which the straight way valves 97, 99 and 101, respectively, are associated. Via the straight way valves 91, 93 and 95, a pressure input 103 communicating with the command pressure line S, communicates with a pressure output 105. The associated straightway valves 97, 99 and 101 of each fluid element communicate on the one side with the pressure output of that fluid element and on the other side with an auxiliary command pressure line S which is common to all fluid elements and which always has an inverse pressure level with respect to the pressure level of the command pressure line S. The signal supplies p, q, r, s, t and u of the fluid element 89 shown communicate with the control pressure linesa, c, e, b, d and f, respectively (compare with FIG. 5).

The operation of the selection system 87 will be described with reference to a pressure level combination in the control pressure lines a, b, c, d, e, and f where the fluid element 89 shown is selected, i.e. 0," l, 0, l, O," l whilst the command pressure lines S and S have the pressure level l and 0, respectively. The following reference numerals now refer only to the shown and selected fluid element 89. At the said pressure level combination the pressure level 1" prevailing in the command pressureline 8 appears at the pressure output 105. As the signal supplies s, t and u have the pressure level 1, the associated straight way valves 97, 99 and 101 are closed so that the pressure level 1 at the pressure output 105 is maintained. If one of the seven other fluid elements is selected while the fluid element 89 has been selected, at least one of the straight way valves 91, 93 and closes and the straight way valve associated with that straight way valve opens, so that via the open associated straight way valve the fluid element 89 is rel ieved by means of the auxiliary command pressure line S in which the pressure level 0 prevails. It will be obvious that in the described manner each selected fluid element is relieved if subsequently another fluid element is selected.

As already stated, the selection systems 33 and 69 operate with the pressure level 1 and the pressure level 0, respectively, in the command pressure line S. It will be obvious that the selection systems 3 and 87 can operate both with the pressure level l and with the pressure level 0 in the command pressure line S. In the selection system 3, if desired, an already selected fluid element may be returned to the nonselected condition upon selection of another fluid element by reselecting the already selected fluid element and by in verting the pressure in the command pressure line S. In the selection systems 33 and 69 this is effected in a simpler manner, i.e. by selecting an element other than the already selected element. This is enabled in the selection system 33 by the air-relief valve associated with each straight way valve, and in the selection system 69 by the automatically operating fluid interrupter associated with each straight way valve. The fact that the selection system 87 can operate both with the pressure level 1 and the pressure level 0 in the command pressure line S is a result of the use of the auxiliary command pressure line S which has an inverse pressure level with respect to the pressure level of the command pressure line S.

However, if in the selection systems 33 and 69 a different type of fluid interrupter is used for the series-arranged fluid interrupters shown in FIG. 2, and the airrelief valves and the associated automatically operating fluid interrupters, respectively, are incorporated the other way around with respect to FIG. 3 and FIG. 6, respectively), it is possible for the selection systems 33 and 69 to operate with the pressure level 0 and the pressure level 1, respectively, in the command pressure line S. This other type of fluid interrupter, shown in FIG. 9, is characterized in that it is open if the control pressure supplied thereto is of the level 0. The

fluid interrupter 107 shown in FIG. 9 comprises a second fluid duct 11 1 which communicates with a first duct 109, which communication may be cut off by a plunger 115 which is movable by the force of a spring 113. The plunger 115 is controlled by means of a control pressure of the level which is supplied via a third fluid duct 117. If the control pressure is of the level l, the plunger 115 is in the position shown, the spring 113 then being compressed. If the control pressure changes to the level 0, the compressed spring 113 is released sothat the plunger 115 is moved over such a distance that the communication between the first fluid duct 109 and the second fluid duct 1 l 1 is cut off. It will be obvious that by using three series-arranged fluid interrupters 107 as shown in FIG. 9 and, as was already stated, inverting the air-relief valves and associated automatically operating fluid interrupters, respectively, the selection systems 33 and 69 can be operated with the pressure level 0 and the pressure level l respectively, in the command pressure line S.

. The fifth selection system 119 according to the invention, as shown in FIG. 10 comprises eight identical logical fluid elements 121 to be selected individually. For the sake of clarity, only one of the'fluid elements 121 of the selection system 119 is shown. The reference numerals placed near the fluid element 121 shown therefore always refer to all eight fluid elements. The fluid elements are selected by means of six control pressure lines a, b, c, d, e and f, the control pressure lines of the pairs of control pressure lines a and b, c and d, e and f always having mutually inverse pressure levels. Each of the eight fluid elements comprises three series-arranged straight way valves 123, 125, 127 as shown in FIG. 2, which communicate via signal supplies p, q and r with one of the control pressure lines a, b, c, d, e and f, a pressure input 135, which communicates with a command pressure line S which is common to all fluid elements, communicating with a pressure output 137 via these straight way valves 123, 125, 127. With the series-arranged straight way valves 123, 125, 127 in a fluid element, an automatically operating fluid interrupter 129, 131, 133, respectively, as shown in FlG. 4 is associated, which communicates on the one side with the pressure output 137 and on the other side with one of the control pressure lines a, b, c, d, e and f via one of the signal supplies s, t and u.

In view of their function, the automatically operating fluid interrupters 129, 131 and 133 will henceforth be termed air-relief valves. The connections of the signal supplies p, q, r, s, t and u to the control pressure lines a, b, c, d, e and f are established in the same manner as in the selection system 33 shown in FIGS. 3 and 5. By means of the signal supplies p, q and r of each of the fluid elements, the control pressure lines communicating with those signal supplies also control one of three series-arranged further straight way valves 139, 141, 143, which in view of their function are henceforth termed restoring valves 139, 141, 143, a restoring pressure input 145, which communicates with the command pressure line S which is common to all fluid elements communicating with a restoring pressure output 147 via the said restoring valves 139, 141, 143. The restoring pressure output 147 communicates via a restoring pressure line 149 with one of the outputs 151 of the selection system. The outputs 151 communicate with further fluid-controlled devices such as, for example, an electrical switch operated by fluid pressure. In the restoring pressure line 149 an automatically operating fluid interrupter 153 as shown in FIG. 4 is incorporated, which is closed at a comparatively high pressure at the restoring pressure output 147 and a comparatively low pressure at the output 151 of the selection system. The fluid interrupter 153 is opened if the same pressure level prevails on both sides thereof. Between the output 151 and the fluid interrupter 153 the restoring pressure line 149 communicates, via an automatically operating fluid interrupter 155 as shown in FIG. 4, with a reservoir 157 in which a comparatively high pressure (of the level l prevails. Due to suitable proportioning, fluid interrupter 155 is opened if on both sides thereof the pressure level is the same, whilst it is closed if the pressure level on output 151 is lower than the pressure level 1 in the reservoir 157 by a given amount yet to be described. The pressure output 137 communicates via a store control line 159 with the output 151, an automatically operating fluid interrupter 161 as shown in FIG. 4 being incorporated in the store control line 159. Viewed from the output 151, the fluid interrupter 161 has a direction of operation which is opposite to the direction of operation of the fluid interrupter 153. In given cases yet to be described, the store control line 159 communicates via an automatically operating fluid interrupter 163 as shown in FIG. 4 with a reservoir 165 of a comparatively low pressure (of the level O). Due to suitable proportioning, fluid interrupter 163 is opened if on both sides thereof the pressure level is the same, whilst it is closed if the pressure level on output 151 exceeds the pressure level 0 in the reservoir 165 by an amount yet to be described.

The operation of the selection system 119 will now be described with reference to a pressure level combination in the control pressure lines a, b, c, d, e and f where the fluid element 121 shown is selected, i.e. 0, 1, O, 1, O, 1, (see also FIG. 5), the command pressure line having the pressure level l. The following reference numerals refer only to the shown and selected fluid element 121. At the said pressure level combination in the control pressure lines, the straight way valves 123, 125, 127 and the restoring valves 139, 141 and 143 are open so that the pressure of the level 1 of the command pressure line S appears at the pressure output 137 and at the restoring pressure output 147. The air-relief valves 129, 130 and 131 are also open because on both sides thereof the pressure level 1 prevails. The fluid interrupter 161 is kept open by the pressure of the level 1 in the store control line 159, so that at the output 151 of the selection system the pressure level 1 prevails. As the pressure level 1 prevails on the restoring pressure output 147, the fluid interrupter 153 also remains open. A further fluid-controlled device is operated by the pressure of the level 1 at output 151. Output 151 being at the pressure level 1, one of the seven non-selected fluid elements 121 is selected by changing the pressure level combination 0, 1, 0," 1, 0, 1, present in the control pressure lines a, b, c, d, e and f to, for example, l," 0, 0," l, 0, 1. As a result, pressure of the level 1 appears in the signal supply p and pressure of the level 0" appears in the signal supply s (see FIG. 5) of the fluid element 121 shown,

and both the straight way valve 123 and the restoring valve 139 are closed. As the pressure level prevails at the side of the air-relief valve 129 facing the signal supply s, and the pressure level l prevails at the side facing the pressure output 137, the store control line 159 is relieved via the open air-relief valve 129 as far as the fluid interrupter 161 which now closes. As the fluid interrupter 161 remains closed due to the pressure level 1 at the output 151, and as also the restoring valve 139 is closed, the pressure level 1 at the output 151 is maintained (memory action). It will be obvious that an arbitrary number of fluid elements may be selected simultaneously. The pressure level combination present in the control pressure lines a, b, c, d, e and f is always the one by which the last selected fluid element is controlled. Returning the output 151 to the pressure level 0, characterizing the nonselected condition, is effected by reselecting the fluid element 121 shown and by bringing the command pressure line which is common to all fluid elements to pressure level 0 for a sufficiently long period. By reselecting the fluid element 121 shown, the restoring valves 139, 141 and 143 are opened so that the restoring pressure line 149 and output 151 which are at the pressure level l change to the pressure level 0 (fluid interrupter 153 was already open). It is obvious that the command pressure line S can be brought to pressure level 1 again only if the fluid element 121 (again) or one of the other fluid elements is selected.

Generally,'a slight leakage loss will always occur in practice when an output 151 is at the pressure level 1, so that the risk exists that the memory action is lost. This leakage loss may occur, for example, on the output 151 itself due to leakage losses in the further fluid-controlled device, or at the area of the fluid interrupter 161 and the restoring valve 139. In order to compensate for such'leakage losses, for example, the restoring pressure line 149 and hence the output 151 communicate with the reservoir 157 having the pressure level 1, via the fluid interrupter 155. The fluid interrupter 155, which is of the type shown in FIG. 4, is

' so proportioned that the fluid interrupter does not close when leakage losses occur. This is made possible by situating the diaphragm present in the fluid interrupter 155 at a sufficiently large distance from the associated stop (see FIG. 4). In the case of an output 151 having the pressure level 0 an analogous phenomenon occurs when the pressure level 0" corresponds to a pressure which is lower than atmospheric pressure. In order to prevent that the pressure level on the output 151 increases, for example, the store control line 159 and hence the output 151, may be madeto communicate with the reservoir 165 having the pressure level 0 via the fluid interrupter 163. Like the diaphragm in the fluid interrupter 155 the diaphragm in the fluid interrupter 163 is also situated at a sufficiently large distance from its stop.

Depending on the type of the further fluid-controlled devices connected to the outputs of one of the described selection systems, such a device will be controlled by pressure of the level l or of the level 0. Because, as already stated, the types of selection system 3, 33, 69, and 87 are in principle suitable for operating with either the pressure level 1 or the pressure level 0 in the relevant command pressure line,

both a further fluid-controlled device operating with the pressure level l and a device operating with the pressure level 0 can be operated by means of all these selection systems. Just like the selection system 33 shown in FIG. 3 could be extended with a portion having a memory action and a restoring facility (mainly by adding the two automatically operating fluid inter rupters and restoring valves in each fluid element), the selection systems 3, 69 and 87 can be extended in an analogous manner with a portion having memory action. Depending on the pressure level used in the command pressure lines, the two automatically operating fluid interrupters required for the additional portion and having memory action and restoring facility will have to be inserted in the storage control line and the restoring pressure line, respectively, the other way around with respect to the arrangement shown in the FIG. 10. If the pressure level 0" is used in the command pressure line so that the selection system controls a further fluid-controlled device operating with the pressure level 0, the said two fluid interrupters are arranged the other way around. As regards the reservoirs of comparatively high and of comparatively low pressure level, nothing changes with respect to the arrangement shown in FIG. 10.

The sixth embodiment of a selection system 167 according to the invention shown in FIG. 11 comprises two series of four identical fluid elements each. For the sake of clarity, of each series only two of the four fluid elements are shown, i.e. the fluid elements 169 and 171 of the one series and the fluid elements 173 and 1750f the other series. The fluid elements 169 and 171 are socalled two-valve fluid elements of the same type as the three-valve fluid element 35 shown in FIG. 3, and the fluid elements 173 and 175 are so-called two-valve fluid elements of the same type as the three-valve fluid element 71 shown in FIG. 6.

For the sake of clarity the air-relief valves present in the fluid elements 169 and 171 are not shown and the associated automatically operating fluid interrupters (see FIG. 3 and FIG. 6) present in the fluid elements 173 and 175 are also omitted. The fluid elements 169 and 171 are selectively controlled by means of four control pressure lines a 1),, c and d,, the pair of control pressure lines a,, b, and c,, d, having an inverse" pressure level. The fluid elements 173 and 175 are selectively controlled by means of four control pressure lines a b c and d which pair-wise also have an inverse pressure level. A command pressure line S, which is common to the fluid elements 169 and 171 communicates with the pressure inputs 177 and 179 of the fluid elements 169 and 171, respectively, said pressure inputs communicating, via two series-arranged straight way valves 181 and 183 and two series-arranged straight way valves 185 and 187, with the pressure outputs 189 and 191, respectively. The straight way valves 181, 183, 185 and 187 are of the type shown in FIG. 2 and are controlled as has already been described with reference to the selection system 33 shown in FIG. 3. A command pressure line S which is common to the fluid elements 173 and 175 communicates with the pressure inputs 193 and 195 of the fluid elements 173 and 175, respectively, said pressure inputs conununicating via two series-arranged straight way valves 197 and 199 and two series-arranged straight way valves 201 and 203, with the pressure outputs 205 and 207, respectively. The straight way valves 197, 199, 201 and 203 are also of the type shown in FIG. 2 and are controlled as has already been described with reference tothe selection system 69 shown in FIG. 6. The pressure outputs 189 and 191 of the fluid elements 169 and 171, respectively, communicate with storage control lines 209 and 211, whilst the pressure outputs 205 and 207 of the fluid elements 173 and 175, respectively, communicate with the auxiliary control lines 213 and 215. For operating four further fluid-controlled devices 217, 219, 221 and 223, the storage control lines 209 and 211 are provided with branch lines 225, 227, 229 and 231, respectively, each of which communicates, via an automatically operating fluid'interrupter as shown in FIG. 4, a straight way valve as shown in FIG. 2 and an output of the selection system, with a further fluid-controlled device. With the branch lines 225, 227, 229 and 231 are associated the automatically operating fluid interrupters 233, 235, 237 and 239, respectively, the

straight way valves 241, 2,43, 245 and 247, respectively, the outputs of the selection system 249, 251, 253 and 255, and the further fluid-controlled devices 217, 219, 221 and 223. Each of the outputs 249, 251, 253 and 255 communicates via a straight-way valve as shown in FIG. 2 and anautomatically operating fluid interrupter as shown in FIG. 4, with a restoring pressure line for the relevant fluid element. For example, the outputs 249 and 251 of the fluid element 169 communicate with the restoring pressure line 265 via the straight way valves 257 and 259, respectively, and the fluid interrupters 261 and 263, respectively, the outputs 253 and 255 of the fluid element 171 communicating, via the straight way valves 267 and 269, and the fluid interrupters 271 and 273, respectively, with the restoring pressure line 275. The restoring pressure lines 265 and 275 communicate with restoring pressure outputs 277 and 279, respectively, which communicate, via two series-arranged restoring valves 281 and 283 as shown in FIG. 2 and two series-arranged restoring valves 2,85 and 287 as shown in FIG. 2, with the restoring pressure inputs 289 and 291 communicating with the command pressure line S The straight way valves 241 and 257 ofthe fluid element 169 and the straight way valves 245 and 267 of the fluid element 171 are controlled by means of the auxiliary control lines 213 and 215 of the fluid elements 173 and 175 respectively.

For the explanation of the operation of the selection system 167, such a pressure level combination is assumed to be present in the control pressure line a,, b c (/1 and in the control pressure lines a b,, c d that the fluid elements 169 and 173 are selected, the command pressure lines S and S having the pressure level 1 and the pressure level 0, respectively. When the fluid elements 169 and 173 have been selected, the straight way valves 181 and 183 and 197 and 199, respectively, are open, so that the pressure level 1 appears at the pressure output 189 and the pressure level 0 appears at'the pressure output 205. As the restoring valves 281 and 283 are also open, the restoring pressure output 277 will also attain the pressure level 1. Via the storage control line 209 the pressure of the level 1 will also be present in the branch lines 225 and 227, so that the fluid interrupters 233 and 235 are opened. Due to the pressure of the level 0 in the auxiliary control line 213 of the selected fluid element 173, the straight way valve 241 is opened so that the pressure of the level l reaches the output 249 of the selection system and operates the fluid-controlled device 217. As the auxiliary control line 215 of the non-selected fluid element has the pressure level 1, the straight way valve 243 is closed so that the pressure of the level l in the branch line 227 cannot operate the fluid-controlled device 219. Like the straight way valve 241, the straight way valve 257 is also opened by the pressure of the level 0" in the auxiliary control line 213, so that on both sides of the fluid interrupter 261 the pressure level l prevails. The fluid interrupter 261 is thus opened, the fluid interrupter 263 being closed by the pressure of the level l in the restoring pressure line 265. Whilst the pressure level 1 prevails on the output 249, the pressure level combination in the control pressure lines a,, b,, c and 01 is changed so that the fluid element 171 is selected, the pressure level combination in the control pressure lines a b 0 and d, being maintained so that the already selected fluid element 173 remains selected. As a result, the store control line 2090f the fluid element 169 is relieved via one of the open air-relief valves (as already stated, not shown for the sake of clarity) and the fluid interrupter 233 closes. As one of the restoring valves 281 and 283 of the fluid element 169 is closed when the fluid element 171 is selected, and the pressure level I is maintained in the command pressure line S,, the pressure level l prevails on both sides of the fluid interrupter 261 so that output 217 of the selection system remains at the pressure level l (memory action). Due to the selection of the fluid element 1*71 pressure of the level 1 appears at the pressure output 191, in the store control line 21 1 and in the branch lines 229 and 231 of the store control line 211, so that the fluid interrupters 237 and 239 are opened. As the pressure of the level O'is maintained in the auxiliary control line 213 of the selected fluid element 173, the straight wayvalve 247 is also opened so that the pressure of the level 1 reaches output 253 of the selection system and operates the fluid-controlled device 221. The pressure of the level l which is present in the command pressure line S, appears at. the restoring pressure output 279 of the fluid element 171 via the open restoring valves 285 and 287, so that the restoring pressure line 275 assumes the pressure level 1. Like the fluid interrupter 237, the fluid interrupter 271 is also opened as on both sides thereof the pressure level l prevails, the fluid interrupter 273 being closed by the pressure of the level l in the restoring pressure line 275. However, as the straight way valves 247 and 269 are also closed due to the pressure of the level 1 in the auxiliary control line 215 of the nonselected fluid element 175, the fluid controlled device 223 is not operated. The operation of the fluid-controlled device 223 in the case of already operated fluidcontrolled devices 217 and 221 is effected-by selecting the fluid element 175, the already selected fluid element 171 remaining selected. Upon selection of the fluid element 175 a pressure of the level 0 appears in the auxiliary control line 215 so that the straight way valves 247 and 269 are opened. The pressure of the level 1 present in the branch line 231 thus reaches the output 255 of the selection system and operates the 

1. A fluid-controlled selection system for the selective transmission of a fluid pressure to fluid-controlled devices to be connected to outputs of the selection system, characterized in that the selection system comprises a number (n) of logical fluid elements, each of which has a pressure output communicating with a pressure input, said communication incorporating at least two (m) fluid interrupters which are arranged in series and which are to be individually operated by a control signal supplied thereto, said system communicating with a number (x) of control pressure lines for the selective control of the logical fluid elements, fluid interrupters of the various logical fluid elements to be operated by a control signal communicating with these control pressure lines so that each of the various fluid interrupters of one of the same logical fluid element communicates with a different control pressure line and the fluid interrupters of the various logical fluid elements each communicate with a different combination of control pressure lines from the total number (x) of control pressure lines.
 2. A selection system as claimed in claim 1, characterized in that in each of the (n) logical fluid elements each of the (m) fluid interrupters is associated with a further fluid interrupter, controlled by one of the control pressure lines, which communicates with a pressure output of the relevant fluid element communicating with an output of the selection system, a fluid interrupter and its associated fluid interrupter being so controlled that the first-mentioned fluid interruptor is open if the last-mentioned associated fluid interrupter is closed, or vice versa, an open associated fluid interrupter establishing a communication between the pressure output and a space having a pressure level different from that of the pressure input of the relevant fluid element.
 3. A selection system as claimed in claim 2, characterized in that the number of control pressure lines (x) is twice as large as the number of first-mentioned fluid interrupters (m), one control pressure line of a pair of control pressure lines each time having a comparatively high pressure level and the other control pressure line having a comparatively low pressure Level, one control pressure line of the said pair communicating with one of the firstmentioned (m) fluid interrupters and the other control pressure lines communicating with the further fluid interrupter associated with the said fluid interrupter, the number of logical fluid elements (n) to be selected satisfying the relation n < or = 2m.
 4. A selection system as claimed in claim 2, characterized in that the pressure output of each logical fluid element each time communicates via a first automatically operating fluid interrupter with an output of the selection system, said output communicating via a second automatically operating fluid interrupter with a space having the same pressure level as the pressure input, the said two automatically operating fluid interrupters, viewed from the said output, having an opposite direction of operation, both automatically operating fluid interrupters being open if the pressure on both sides of the relevant fluid interrupter is the same.
 5. A selection system as claimed in claim 3, characterized in that in each fluid element each of the control pressure lines controlling a fluid interrupter of the first-mentioned number (m) of series-arranged fluid interrupters, also controls a further number (m) of series-arranged fluid interrupters which is equal to the first-mentioned number, via which fluid interrupters the first-mentioned pressure input or a further similar input communicates with the output of the selection system associated with the relevant fluid element, an automatically-operating fluid interrupter being incorporated or not incorporated in the said communication.
 6. A selection system as claimed in claim 1, characterized in that the pressure output of each of the fluid elements has a number of branches, each of which each time communicates, via an automatically-operating fluid interrupter and a further fluid interrupter, arranged in series therewith and controlled by an additional control pressure, with an output of the selection system, said output communicating, via a further fluid interrupter which is also controlled by the said additional control pressure and a further automatically operating fluid interrupter arranged in series therewith, with a restoring pressure output which communicates, via a number of series-arranged similar fluid interrupters which is equal to the first-mentioned number of series-arranged fluid interrupters, with the said pressure input or a further similar fluid input, each of the last-mentioned fluid interrupters being controlled by one of the control pressure lines by means of which one of the fluid interrupters from the first-mentioned number of series-arranged fluid interrupters is already controlled, the said additional control pressure each time originating from the pressure output of one of a number of further fluid elements as claimed in Claim 1 which is equal to the said number of branches.
 7. A selection system as claimed in claim 6, characterized in that each of the outputs of the selection system communicates, via a first automatically operating fluid interrupter, with a reservoir having a comparatively high pressure level and, via a second automatically operating fluid interrupter, with a reservoir having a comparatively low pressure level.
 8. A selection system as claimed in claim 5, characterized in that the pressure outputs and restoring pressure outputs of the selection system communicate with a fluid-controlled device, comprising a number of mutually parallel electrically conducting flexible contact strips situated in a first plane, and a number flatly situated mutually parallel flexible contact strips which are situated in a second plane parallel to the first plane and which cross the contact strips of the first plane, the contact strips of the first plane being separated from the contact strips of the second plane by means of a plate-shaped insulator, in which at the area of a cross-point apertures are made which are at least partly Limited on the one side by a contact strip of the first plane and on the other side at least partly by a contact strip of the second plane, at least one of the two co-operating contact strips at each crosspoint in a row of crosspoints communicating with a pressure output, common to all crosspoints of that row, of one of the fluid elements of the selection system for transmitting a fluid signal having a comparatively high pressure level to a row of crosspoints via a fluid interrupter associated with each of the crosspoints and communicating with one of the pressure outputs of one of the fluid elements of a selection system, for the selective admission of the said fluid signal each time to one of the crosspoints of the row, as well as via an automatically operating fluid interrupter which is arranged in series with a further automatically operating fluid interrupter which communicates with a restoring pressure output of the said fluid element of the selection system which is common to all crosspoints in the said row.
 9. A selection system as claimed in claim 8, characterized in that the contact strips are permanently connected to the surface of the plate-shaped insulator.
 10. A selection system as claimed in claim 8, characterized in that each of the contact strips cooperating at the area of a crosspoint closes off the relevant side of the aperture in the plate-shaped insulator.
 11. A selection system as claimed in claim 8, characterized in that at least one of the two mutually co-operating contact strips communicates at each of the crosspoints via a first automatically operating fluid interrupter with a first reservoir having a comparatively high pressure level and via a second automatically operating fluid interrupter with a second reservoir having a comparatively low pressure level, the first and the second automatically operating fluid interrupter, viewed from the contact strips, having an opposed direction of operation. 